Numerous drinks and foods are available for consumption. Most drinks and foods do not take advantage of under utilized resources--whey, milk and their components.
Cow (bovine) milk contains about 87 percent (%) water, 3% casein, 0.65% whey protein, 4.5% to 5.0% lactose, 3% to 4% milk fat, 0.3% to 0.7% mineral salt plus a variety of water and fat soluble vitamins, lactic and citric acids, urea, free amino acids and polypeptides. In the manufacture of cottage cheese or casein, the milk fat is first separated centrifugally (as cream) and the casein fraction of the milk is then precipitated at its isoelectric point by the addition of acid. The precipitated casein, about 1/10th of the original weight of the milk, is then treated to yield the desired casein product. The remainder of the original milk, containing all of the other components listed above, is called whey.
For other cheeses, the process varies somewhat. The whole or part skim milk is treated with an enzyme (such as rennet, porcine pepsin or a vegetable enzyme) to coagulate and precipitate casein. The precipitated casein, called "curd", is cut and treated in a suitable manner to yield the desired cheese, with the remainder of the original milk, called whey, being drained off the curd.
The average composition of whey obtained from ordinary cow milk (whole milk) is 93 (weight percent) wt. % water, 1 wt. % protein, 0.3 wt. % fat, 5 wt. % carbohydrates and 0.7 wt. % ash. Whey often has a pH in the range of about 4 to about 7 but raw whey can be neutral, acidic or basic. For example, cheese whey from Cheddar, Swiss or Italian cheese has a pH of 5.8 to 6.2 whereas whey from cottage cheese has a substantially lower pH.
Whey, because of its about 5.6 to about 6.5 wt. % solids content, has long been recognized as a serious pollutant. However, its protein content (about 0.6 to about 0.8 wt. %) has untapped commercial value and the unusual property of being acid soluble. Whey protein also has an excellently well balanced ratio of essential amino acids making it a satisfactory source of protein for food fortification. The water and other solids of whey and milk do not now have high commercial value.
Whey can be subjected to filtration to produce a retentate and permeate that, for example, can be incorporated into a drink. European Patent Application Nos. 0 019 415 (Stauffer Chemical Company) and 0 364 053 (DMV-Campina P.V.) disclose drinks made from retentate and permeate, respectively.
It would be desirable to add value to milk, whey and their components. The present invention satisfies this desire.